When optical instruments with low magnification are designed, particularly for men with hypoacuity, one of the emerging problems is to provide a comparatively wide field of view along with the adequate quality of the obtained image, i.e. the image should be distinct sharp, colourless etc.
Telescopic optical systems used at present in such optical instruments have an angle of view which does not exceed, as a rule, 17 degrees. Moreover, most of these optical instruments are heavy and are not comfortable enough in use. The present invention is directed at making the optical instruments of low magnification more comfortable in use and at improving the parameters of telescopic optical systems applied therein.